Peter's explorations in technology

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Here’s a poor photograph showing an Apple IIe running Sprite Logo for the first time. The left monitor connects to the Apple II’s normal video out, and the Apple CRT connects to the sprite card. The normal video out is useless while running Sprite Logo, which makes sense because most users wouldn’t have two monitors. The sprite card goes in slot 2 and requires an additional ground connection to the power supply chassis, per the manual. The Apple IIgs is not connected to any visible displays and serves as an overpriced monitor stand. Even after a short period, the sprite card became very warm to the touch, which is consistent with a warning in the manual about heat production.

I look forward to exploring some of the unique capabilities of Sprite Logo.

A short pigtail brings the composite video connection to the outside of the computer case. The sprite card does not display normal Apple II video, and the user must switch the cable between the sprite card and normal video output when switching between software designed for the card and other software. There’s a separate ground lead from the composite connector to the power supply. I’ve never seen a similar separate ground lead on any other peripheral card. Perhaps LCSI had trouble passing the FCC tests and added this ground as the least expensive fix.

This card includes a 2 KB EPROM. A ROM (or EPROM) allows reliable software detection of the card. However, 2 KB is too large for this function alone. Since the 64 KB main memory of the Apple II is limiting for Logo, I expect the designers used the extra space for Logo-related code or data. I’ll examine the contents in a later post. There’s a second unpopulated (U14) ROM footprint. Perhaps LCSI considered using lower density EPROMs or more EPROM.

The decoupling capacitors (C1 – C10) are too large for the PCB footprints. Notice how the leads are bent at odd angles to make the available parts fit.

There are two unplated holes (one near C13 and another near U1) in the PCB. I have no idea why these exists. Perhaps they’re mounting holes used during manufacturing, or perhaps they’re harmless errors in the board design.

Continuing my exploration of LCSI’s “Sprite Logo”, let’s break the shrink wrap and open the box. These photographs preserve the original packing order. Despite dirt and water damage to the exterior, the box contents appear pristine.

LCSI “Sprite Logo” comes in a large cardboard box with similar design to the “Apple Logo” box. Compared to “Apple Logo”, the “Sprite Logo” box is larger, more colorful, and displays patterns that suggest interconnections between multiple turtles. Notice the turtles taking on different shapes, such as an airplane, flower, dog, cat, or truck. The subtitle promises “An Exciting, Interactive, Computer Language Featuring Multiple Dynamic Turtle Graphics.”

The back of the box provides some details. The text does not compare Sprite Logo to Apple Logo but does emphasize words that set Sprite Logo apart like “interactive”, “dynamic” “colorful”, “moving”, and “animation”.

Sprite Logo
A dynamic, powerful and friendly language system for the Apple II family.

Sprite Logo is an exciting interactive computer language with complete dynamic graphics capabilities. Sprite Logo is easy for beginners to learn and use. It is a powerful modern programming language which experienced programmers will find a continuing challenge.

is a language for learning: adults and children quickly and easily begin to write programs and acquire valuable problem solving skills

is a modern, procedural programming language with list processing, recursion, arithmetic and other mathematical capabilities

enables you to create animation, simulations and other educational software

System Requirements
To use Sprite Logo you should have one of the following systems:

An Apple IIe Computer or an Apple II or II Plus with 64K of memory

An Apple II disk drive with a 16-sector disk controller card

A color TV or monitor is preferred but Sprite Logo can be run with a monochrome display

Curiously, the box does not mention an enclosed hardware card, and the only sign that the box contains hardware is the FCC ID (CJU79JSPRITE) on the left side. The ID is on a sticker, suggesting that the boxes were printed prior to receiving the ID. The FCC database shows that LCSI received approval on 2/16/1984. The bottom of the box has a stamped number, 2575, that is likely the serial number for the contained hardware card.

“Sprite Logo” stands out in this list due to the price. It’s 3 times more expensive ($299 vs. $100 MSRP) than any other version. Over the next few weeks, I’ll explore Sprite Logo, why it’s so expensive, and what’s unique.

This is an updated, ProDOS based, 128KB version of the original Apple Logo.

Apple Sprite Logo (from LCSI)

$299

A variation of Apple Logo with a “sprite board” enabling “multiple dynamic turtle graphics.” This version was unpopular due to the price.

Terrapin Logo

$99 ($65 retail)

Based on MIT Logo. Terrapin offered multiple upgraded versions throughout the life of the product and a nice manual. Version 3.0 added 128KB support in 1985. See page 92 of “Creative Computing” (December 1984) for the retail price.

Krell Logo

$99 ($73.95 retail)

Based on MIT Logo. Included a poster, introductory “Alice in LogoLand” disk, and minimal documentation. Krell Logo did not receive updates during its lifespan. See page 95 of “Creative Computing” (December 1984) for the retail price. Note that page 95 contradicts page 106 and states the MSRP as $89.95.

I joined the Mold Making class with the Central Oregon Makers last week. Before going, I had no idea how to make a mold or what I might use it for. Although 3D printing (“additive manufacturing”) gets most of the attention, mold making and casting seem like useful and versatile tools for duplicating and fabricating items. I could see using this technique to repair or replace small latches, wheels, key caps, housings, and decorative features where an original is available. For example, I’ve had trouble finding robot wheels I like, but now I can make my own.

It’s nice to have another tool in my toolbox, and I expect to invent problems just to use this tool.

Play-i is an interesting start-up using robotics to teach programming concepts to children as young as 5 years old. From the company’s marketing material, here’s the vision:

“In starting Play-i, we set out to create the product we want our children to have. Our mission to make computer programming accessible for every child is bigger than we are.

We need to re-think education. Students are becoming great at retaining facts, but there’s not enough focus on teaching them how to think. We are preparing our children… and your children for the future by inspiring curiosity and igniting a love for learning.”

Details on their system are a bit scarce, but I find their effort fascinating because:

Play-i is designed for young children. Most commercial robots, even those advertised for education, are unsuitable for younger children. The robots require assembly, are relatively fragile, and have exposed electronics. Of course, older or more experienced folks might prefer these things, but the system seems to have sufficient capabilities for both beginner and more advanced learning.

Programming is hands-on and eye-level. Many other robots require a desktop computer, cables, and software installation. In contrast, Play-i promises programming with a tablet while sitting on the floor next to the robot. Hopefully, this system will provide immediate feedback, gratification, and interaction. The robot will support several programming languages, which should allow the robot to grow and teach a wide variety of skills and ages. I think the success of the robot will depend on the supporting software, programming interfaces, and curriculum.

The robots have “personalities” and names. The stories, colors, and shapes associated the robots seem to build an emotional relationship between humans and their robot pets, and I suspect that children will find this anthropomorphism appealing.

I do have some concerns but none ought to block their goals. Specifically, the hardware is closed and lacks a supported way to “hack the hardware.” There is an interface for add-ons, but the add-ons appear to be cosmetic or mechanical like an arm, handle, or cape. I think the closed hardware design is necessary for young children but might limit some types of exploration.

Play-i does promise a developer API, which will likely be key to building a rich, capable software infrastructure and curriculum around the physical robot. The robot appears to offer quite a bit of capability and flexibility with multiple programming interfaces, options for customization, a decent set of sensors, and a decent set of actuators.

The Living Computer Museum opened October 2012 in Seattle, WA. Unlike most museums that strive to preserve artifacts how they find them, usually broken and powered off, this museum keeps their machines alive. They’re in working condition, complete with the strangely beautiful sounds of teletypes, Disk ][ drives, paper tape, and raised-floor cooling. The museum is the vision of Paul Allen, co-founder of Microsoft. Allen cut his teeth on PDP minicomputers, and the museum’s collection reflects this but has a growing display of personal computers. I know little about the PDP series and vintage of machine, but I found the museum irresistibly fascinating and essential for everybody interested in computers.

I visited the museum last year shortly after its opening, and you may read my full report in Juiced.GS (Volume 17, Issue 4). And, yes, I should’ve posted this a year ago, but I somehow left the post as a draft … in my defense, it’s only a single-bit memory error.